<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      function fn() {
        return class {
          money = 1000;
        };
      }

      class Animal {
        money = 1000;
      }

      class cat extends fn() {}
      class cat extends Animal {}
    </script>
  </body>
</html>
